When REST is the wrong shape for the problem, GraphQL and gRPC each fix a different pain — and each buys that fix with a new cost you have to design around.
When REST isn't the right shape: GraphQL (client-selected fields, and its N+1 / caching / complexity costs) and gRPC (Protobuf, HTTP/2, streaming, codegen) — plus a decision framework for REST vs GraphQL vs gRPC.
The Picnic social platform served 1M+ users across a graph of Go microservices behind a GraphQL gateway. The latency win came from a counter-intuitive move: fewer services, tighter contracts.
100K+ votes, 10K+ concurrent users during a live AFL Brownlow Medal broadcast. The architecture: Go on Cloud Run, GraphQL + gRPC behind a CDN, vote integrity through Cloud KMS + Security Command Center. Notes on what makes a live-broadcast load shape unusual.